Outdoor grills are well-known. In fact, grilling out has become increasingly popular in recent years. Over the years, there have been numerous improvements made to grills.
There are two basic types of outdoor grills—charcoal barbecue and gas grills. Gas grills offer a major advantage of less preparation time because the gas is instantaneously available. Generally, gas barbecue grills consist of a frame or support structure and a cooking chamber. Grills can be configured to hold or support the heating elements and a fuel tank on the side or inside a cabinet. Gas grills have a burner element adjacent to the lower portion of the chamber with a cooking surface near the top of the chamber. Gas grills almost universally have a hood or cover which can be lifted up or pivoted to permit access to the cooking surface. There can also be an auxiliary cooking element located inside or on the side of the grill for cooking.
Many older types of charcoal grills produce smoke, steam, or other gaseous byproducts because they use charcoal. This is considered beneficial as it provides great flavor to the food. Often, in other grills, it is considered beneficial to incorporate some type of flavoring system to utilize and enhance the airborne smoke, such as a racking system. However, there are a number of drawbacks in using charcoal grills. One drawback is the increased potential for flaming up due to greases, oils, and similar flammable liquids dripping onto the hot coals. Furthermore, there typically is a long startup process as well as longer operating times needed to properly cook on these grills. Finally, charcoal does not provide adequate heat control.
Modern gas grills may overcome some of the problems with charcoal grills but have their own set of drawbacks. For example, most existing gas grills take the form of an oven which holds the heat and flame below a cooking surface and can be selectively activated to cook certain areas in a long line. This entrapment of heat provides for an even distribution of heat like an oven, but this heat trapping only produces radiant heat for cooking. Some gas grill manufacturers put a single plate with various-sized holes underneath the cooking surface but this method just causes heat to concentrate near the larger holes. This design, with the different sized holes results in a least-resistance system of heating. In essence, the heat goes through the large holes unhindered but is limited when trying to go through the small holes. The result is hot spots on the cooking surface and therefore uneven cooking.
The below-referenced U.S. patents, disclose embodiments that were at least, in part, satisfactory for the purposes for which they were intended. The disclosures of all the below-referenced prior United States patents in their entireties are hereby expressly incorporated by reference into the present application for purposes including, but not limited to, indicating the background of the present invention and illustrating the state of the art.
U.S. Pat. No. 6,314,871 entitled “Cooking Appliance with Improved Heat Distribution” describes a sear grid that has an undulating shape located between the burner and the cooking grid and a panel that has radius peaks to allow liquids to run off and be heated. This plate has only limited holes at the bottom for draining and at the other edge for heat to rise to the cooking surface. This single plate design results in basically an oven environment, which does not permit flavoring of the items being cooked, nor does it offer any method for ease of use or cleaning.
U.S. Pat. No. 5,806,412 entitled “Gas Cooking Apparatus” provides a single sheet baffle inside the grill combustion chamber and a plurality of various size openings for controlling combustion gas travel and evenly distributing heat.
Cooking arrangements for long gas burners are also widely known in the art. A cooking surface is incorporated into an opening that is positioned between different sections of the cooking surface or extends along the back underside of the cooking surface. This type of heating element has several known problems. One problem is that if not protected from above, grease and other liquids may fall on to the burner, where the heat and flame burn the grease causing a flare up. This burning also causes a buildup of carbon and burned grease residue on the burner to the point that they will fail to operate over time.
There are several other problems that may arise when using long-type burners. For example, spiders, insects or other debris may get into the burners and inhibit proper operation. To provide a uniform heat distribution, grill manufacturers have placed lava rocks between the cooking surface and the burner elements to act as a conductive component, absorbing and radiating heat to the cooking surface. However, the pores of lava rocks trap fluids and food creating an unsanitary condition with a potential for insects and bacteria. Furthermore, the accumulated buildup of grease, food and charred items can block the passage of heat. Some manufacturers have attempted to solve this problem by using bricks instead of lava rocks to control the heat and temperature, but have encountered many of the same problems as with lava rocks.
In some gas grill designs, such as those mentioned above, plates are arranged between the cooking surface and burners to prevent flare-ups and material buildup on the burners. However, these plates effectively function as shields by stopping all direct flame and heat contact with the food on the cooking surface. Furthermore, these plates prevent any liquids from reaching the burner flame which is necessary to produce the smoking flavor effect. Manufacturers have attempted to solve the shielding and lack of flavor problems in different ways. Weber-Stephen Products Company was the first to place inverted V plates, i.e., “flavor bars”, in two layers. These inverted V plates direct fluids away from the heating elements but typically become very hot. This, in turn, causes liquids to sizzle and evaporate rapidly upon contact with the flavor bars and end up leaving behind a buildup. Also, these flavor bars were not designed for any kind of cleaning. Instead, they must be removed and replaced when they no longer function properly. Other manufacturers have utilized plates to capture heat while blocking fluids from reaching the heating elements. The result is that the grill is essentially turned into an oven, but is still called a grill. In fact, many grill manufacturers describe their grills as an “oven like environment”.
Depending on factors such as the food to be cooked and the height of the particular individual who is cooking, it may be desirable to vary the distance between the cooking surface and the burners. However, in a typical gas grill, the vertical distance between the cooking surface and gas burners is fixed. For some foods, it is considered beneficial to be able to arrange a burner closer to the cooking surface to increase the heating and cooking speed, especially when searing foods. Another benefit of lowering a cooking surface relative to the heat source is to more easily control different portions of the cooking surface to achieve hotter temperatures. However, with the typical gas grill, there is no way to safely or easily adjust the cooking surface, and therefore the cooking temperature. Instead, these gas grills utilize higher BTU heating sources to compensate for the lack of height adjustability.
An additional problem with existing gas grills is that the typical large and long heating elements provide limited control of surface temperatures. One approach taken to solve this problem was to add more elements. However, these U-shaped elements, long single burner elements, and four- or five-element arrangements are not being used to control heat and surface temperatures. Instead, these elements provide a large area of heating and a large temperature rise from the output of the element. The heating elements are controlled through the use of a valve and knob supplying gas to the heating elements. At low temperature settings, the flame may be so small that just a small amount of air movement causes the flame to go out. The ideal temperature setting for this style of grill is somewhere in the mid-range. At high temperature settings, it has been noted that on some grills, the large demand for gas has turned off the gas supply by activating the tank safety valve. While this is a beneficial tank safety feature, some users are forced to look at other methods for fueling their grill.
Another problem with gas barbecue grills is the ability of a typical user to properly assemble the grill. Poor installation instructions coupled with long assembly times contribute to this problem. One typical design of a gas grill has a frame and components fastened only with screws that if improperly installed, can cause structural weaknesses. Furthermore, over time, even properly installed fasteners can rust and lose holding power with the result being weakened grills that may eventually fall apart. Recently, stainless steel grills have become a popular alternative. Stainless steel grills provide the look and design of grills made by other materials. However, stainless steel grill components are sometimes difficult to assemble due to the hardness of the metal causing screws to not attach properly or to strip the threads of the screw or hole.
Another problem with present grills is the inability to add features to them at a later time. This is especially a problem with high-end units. For example, if a consumer does not have enough money to purchase a high-end unit, he must either wait or purchase a unit with less functionality and features.
Existing rotisserie systems for gas grills have a number of problems. For example, if an uneven load is placed on the rotisserie shaft, the item may cook unevenly or the motor may stall. Furthermore, the uneven load may cause the motor to run faster if the load is rotating downwards and slower if the load rotating upwards. This obviously creates problems with food quality as well as problems with the motor including popping off the assembly or lifting off the attachment points on the grill.
A still further problem with current gas grills is with the burner ignition system. Currently, in a low gas setting, the burner flames may be blown out with no indication of this to the user. Furthermore, when lighting a grill, the igniters continually fire sparks until the burner elements are lit. Sometimes, the lighting does not occur for several seconds allowing a buildup of gas. Once the burner is lit, the buildup of gas ignites causing the user to see and feel a bang.
A further problem with a grill having large burners or one that produces high BTUs, is that a standard tank of propane (“LP”) does not last for very long. Therefore, a user must purchase spare LP tanks or find another method of providing fuel to their large grill. However, there currently is no kit that can easily change a grill from LP to natural gas. A further problem exists in that no present grill accurately monitors the amount of fuel left in the tank and notifies the user accordingly. Mechanical methods have been used to show the weight of the tank, but tanks differ in weight from manufacturer to manufacturer so these methods are inherently inaccurate. Further, some grills have shut off valves and regulators inline with the tank while others have this equipment separate. There exists a need for an accurate method of detecting the level of fuel and displaying that level along with a calculated cook time remaining.
A further problem with present grills involves the collection of ash, grease and other drippings in special collection trays. Replacement trays are not readily available in stores and typically only available directly from grill manufacturers. A user must presently blindly clean out these trays because there is no indication when they are filled. The typical tray is located at a collection point at the bottom of the chamber. The ash, grease and other drippings remain in the pan indefinitely until it is clear it is filled, e.g., by overflowing.
Therefore, there exists a need for a gas grill that overcomes the aforementioned problems with present grills. A need exists for a grill with an integrated energy/flavor system using round burners having a porcelain or stainless steel protection system providing an accurate temperature control, proper venting and air flow, an improved rotisserie system, having the ability to be cleaned, and modular in design. There exists the need for a grill capable of having precise control of the grill functions, including temperatures, and zones. There exists a need for a grill with a shallower profile for improved heat extraction to the cooking chamber. There exists a need for a grill giving a user the ability to see and retrieve the contents in the cook top. There exists a need for a grill with a modular base unit design wherein additional features can be added at a later time. There also exists a need for a grill having an innovative rotisserie design.